<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		*{
			margin: 0;
			padding: 0;
		}
		body{
			height: 100%;
		}
		#x{
			display: block;
			margin-left: 15%;
			text-align: center;
			font-size: 40em;
			float: left;
		}
		#xu{
			margin-top: 10%;
			font-size: 2em;
			float: left;
		}
	</style>
</head>
<body>
	<span id="x">0</span>
	<span id="xu">+1s</span>
	<script>
	var x=document.getElementById("x");
	var y=document.getElementById("xu");
	var j=0;
	function jia(){
		j++;
		x.innerHTML=j;
	}
	function xu(){
		y.style.display="none";
		setTimeout(xu1,100);
	}
	function xu1(){
		y.style.display="block";
		setTimeout(xu,100);
	}
	var t=setInterval(jia,200);
	setTimeout(xu,100)
	</script>
</body>
</html>